Nowadays, storage systems are increasingly subject to attacks. So the security system is quickly becoming mendatory feature of the data storage systems. For the security purpose we are always dependent on the cryptography techniques. These techniques take the performance costs for the complete system. So we have proposed the Java File Security System(JFSS). It is based on the on-demand computing system concept, because of the performance issues. It is a greate comback for the system performance. The concept is used because, we are not always in need the secure the files, but the selected one only. In this paper, we have designed a file security system on Windows XP. When we use the operating system, we have to secure some important data. The date is always stored in the files, so we secure the important files well. To check the proposed functionality, we experiment the above said system on the Windows operating system. With these experiments, we have found that the proposed system is working properly, according to the needs of the users
